Question: $ \left(\dfrac{9}{4}\right)^{3}$
$= \left(\dfrac{9}{4}\right)\cdot\left(\dfrac{9}{4}\right)\cdot \left(\dfrac{9}{4}\right)$ $= \dfrac{81}{16}\cdot\left(\dfrac{9}{4}\right)$ $= \dfrac{729}{64}$